#include<iostream>
using namespace std;
int main() {
	int n, x, y, sy;
	cin >> n >> x >> y;
	sy = n - y/x;
	if(y%x != 0) {
		sy = sy-1;
	}
	if(sy < 0) {
		sy = 0;
	}
	cout << sy << endl;
	return 0;
}
